5 48 TEMPORARY STRUCTURES
48-1 General
48-1.01 General
48-1.01A Summary
Section 48 -1 includes general specifi cations for constructi ng temporary structures . If a railroad company is involved, f alsework, temporary supports, and jacking support systems must comply with any additional requirements of the railroad company. Section 11 does not apply to temporary structures.
48-1.01B Definitions
frame: Portion of a bridge between expansion joints. jacking: Positioning of new or existing structure s or portions thereof , by jacks or other mechanical methods. previously welded splice: Splice made in a temporary -structure member in compliance with AWS D1.1 or other recognized welding standard , before contract award. temporary -structure adjustment : Grading or adjusting of te mporary structures.
48-1.01C Submittals
48-1.01C(1) General
Submit 6 copies of shop drawings and 2 copies of calculations for:
1.Falsework
2.Temporary supports
3.Temporary decking
4.Jacking Adjustment
48-1.01C(2) Temporary -Structure Inspection Report
Temporary -structure inspection report s must be:
1.Prepared d aily during jacking and temporary -structure adjustment activities . Reports must be submitted: 1.1. By close of business the following business day. 1.2. Before opening the roadway on or under the temporary structure to traffic .
2.Prepared b efore placing concrete . The temporary -structure inspection report must be prepared , sealed, and signed by the temporary - structure engineer. The temporary -structure inspect ion report must include :
1.Descri ption of the progress of the jacking and adjustment activities
2.Descr iption and evalua tion of the condition of the temporary structure and supported structure
3.Inspection findings and the certifications listed in secti on 48 -1.01D(2) that are completed by the temporary -structure engineer
48-1.01C(3) Adjustment Plan Shop Drawings
Submi t adjustment plan shop drawings if the falsework or temporary supports are to be adjusted more than 1/2 inch. The adjustment plan shop drawings and calculations must be sealed and signed by the temporary - structure engineer. Adjustment plan shop drawings and calculations must include:
1.Methods and sequencing for the adjustment. SECTION 48 TEMPORARY STRUCTURES
2.Descriptions of equipment to be used.
3.Location o f jacks or other adjustment equipment.
4.Detailed sequence for releasing of bracing.
5.Details and calculations for the stability and adjustment of the falsework or temporary supports during all stages of the adjustment including any additional required temporary bracing.
6.Calculations that include stresses, deflections, and loads in all load carrying members, bracing, and equipment as well as any redistributed loads resulting from the adjustment. Calculations m ust also include the effect of the adjustment sequence.
48-1.01D Quality Assurance
48-1.01D(1) General
Reserved
48-1.01D(2) Temporary -Structure Engineer
The temporary -structure engineer must :
1.Be registered as a civil engineer in the State.
2.Have experience in temporary structure de sign or temporary structure construction inspection.
3.Seal and sign the shop drawings.
4.Be present during all jacking and adjustment activities.
5.Prepare, seal, and sign a daily temporary -structure inspection report during jacking and temporary - struc ture adjustment activities .
6.The temporary -structure engineer must inspect and certify that: 6.1. Temporary structure is stable before jacking activities or adjustments and before concrete is placed. 6.2. Temporary structure complies with the authorized shop drawings. 6.3. Materials and workmanship are satisfactory for the work.
7.Stop activity if any unanticipated issues occur.
8.Propose revisions to the authorized shop drawings to address any issues. Do not resume temporary structure activities until the proposed revisions are authorized. The temporary -structure engineer may assign a representative to perform the temporary structure activities specified in section 48 -1.01D . The temporary -structure engineer must submit a letter that is sealed and signed certifying that the representative :
1.Is registered as a civil engineer in the State
2.Has experience in temporary structure design or temporary structure construction inspection
3.Is familiar with the authorized shop drawings and the stresses the members are required to sustain
4.Will a ttend at least 1 job site visit with the Engineer and your temporary -structure superintendent to discuss the authorized shop drawing s
48-1.02 Materials
Not Used
48-1.03 Construction
Not Used
48-1.04 Payment
Full compensation for work specified in section 48 is included in the payment for the bid items involved unless:
1.Bid item for the work is shown on the Bid Item List
2.Work is specified as change order work
48-2 Falsework
48-2.01 General
48-2.01A Summary
SECTION 48 TEMPORARY STRUCTURES You must design, construct, and maintain falsework that:
1.Is safe and adequate
2.Provides the necessary rigidity
3.Supports the imposed loads
4.Produces a completed structure that conforms to the lines and grades shown
5.Includes illumination for vehicular and pedestrian traffic Falsework used as temporary supports must comply with section 48 -3.
48-2.01B Definitions
independent support system: Support sys tem that is in addition to a falsework removal system that employ s methods of holding falsework from above by winches, hydraulic jacks with prestressing steel, HS steel rods, or cranes. falsework release: Lowering of falsework to the point that it no longe r supports the loads imposed by the permanent structure, or any element, that the falsework was designed to support during construction. Falsework release includes blowing sand from sand jacks, turning screws on screw jacks, and removing wedges. falsework removal: Releasing, lowering, and disposing of the falsework.
48-2.01C Submittals
48-2.01C(1) General
Submit a certificate of compliance for each delivery of structural composite lumber used in falsework. Submit a certificate of compliance for the timber used to construct falsework. The certificate of compliance must verify the grade and species of the timber. Submit a letter of certification that certifies all components of manufactured assemblies are used in compliance with the manufacturer's inst ructions. If requested, (1) submit manufacturer's data for manufactured assemblies to verify manufacturer's instructions or (2) perform tests demonstrating adequacy of the proposed assemblies. Submit field acceptance criteria for falsework piles with a cal culated nominal resistance greater than 200 tons. Base acceptance criteria on a wave equation analysis performed on dynamic monitoring of falsework pile driving. Analyses must be sealed and signed by an engineer who is registered as a civil engineer in the State. Submit acceptance criteria before falsework erection is complete. Submit a letter of certification for all falsework members with welded splices. The letter must certify that all welding and NDT, including visual inspection, comply with the Contrac t and the welding standard shown on the shop drawings. The letter must be sealed and signed by an engineer who is registered as a civil engineer in the State. Submit the letter before placing any concrete on the falsework being certified. Submit a welding certification for falsework members with previously welded splices. The certification must:
1.Itemize the testing, inspection methods, and acceptance criteria used
2.Include tracking and identifying documents for previously welded members
3.Be sealed an d signed by an engineer who is registered as a civil engineer in the State
4.Be submitted before erecting the members Submit a falsework lighting plan at least 10 days before starting construction on falsework containing openings for vehicular traffic, p edestrians, or railroad. The plan must include:
1.Location, spacing, and mounting heights of luminaires
2.Types of luminaires
3.Calculations of i llumination levels used to determine placement of luminaries
4.Plot of illumination points used to demonstrate compliance with the illumination levels requirements SECTION 48 TEMPORARY STRUCTURES
5.Lighting circuit diagrams
48-2.01C(2) Shop Drawings
Submit shop drawings and calculations for falsework. The falsework shop drawings and calculations must be sealed and signed by the tem porary -structure engineer for any of the following conditions:
1.Height of any portion of the falsework measured from the ground line to the soffit of the superstructure is more than 14 feet
2.Any individual falsework clear span is more than 16 feet
3.Falsework contains openings for vehicular, pedestrian, or railroad traffic
4.Falsework removal systems support falsework from above by winches, hydraulic jacks with prestressing steel, HS rods or cranes Shop drawings and calculations for falsework piles w ith a calculated nominal resistance greater than 100 tons must be sealed and signed by an engineer who is registered as a civil or geotechnical engineer in the State . Falsework shop drawings and calculations must include:
1.Details of erection and removal activities.
2.Methods and sequences of erection and removal, including equipment.
3.Maximum falsework adjustment height.
4.Details for the stability of falsework during all stages of erection and removal activities.
5.Superstructure placing diagram sh owing concrete placing sequence and construction joint locations. If a schedule for placing concrete is shown, no deviation is allowed.
6.Assumed soil bearing values for falsework footings.
7.Maximum horizontal distance falsework piles may be pulled for placement under caps.
8.Maximum deviation of falsework piles from vertical.
9.Anticipated total falsework and form work settlements, including footing settlement and joint take -up.
10.Grade, species, and type of any timber or structural composite lumber. Include manufacturer's tabulated working stress values for composite lumber.
11.Design calculations that includ e stresses and deflections in load carrying members.
12.Provisions for complying with temporary bracing requirements.
13.Welding standard use d for welded members , including previously welded splices .
14.The following information f or falsework removal systems employing methods of holding falsework from above by winches, hydraulic jacks with prestressing steel, HS steel rods, or cranes: 14.1. Design code used for the analysis of the structural members of the independent support system . 14.2. Provisions for complying with current Cal/OSHA requirements . 14.3. Load tests and ratings within 1 year of intended use of hydraulic jacks and winches . 14.4. Location of the winches, hydraulic jacks with prestressing steel, HS steel rods, or cranes . 14.5. Analysis showing that the bridge deck and overhang are capable of supporting all loads at all time. 14.6. Analysis showing that winches will not overturn or slide during all stages of loading . 14.7. Location of deck and soffit openings if openings are needed . 14.8. Details of repair for the deck and soffit openings after falsework removal . Submit separate falsework shop drawings and calculations f or each:
1.Single bridge or portion of bridge
2.Frame for multi -frame bridges
48-2.01D Quality Assurance
48-2.01D(1) General
Reserved SECTION 48 TEMPORARY STRUCTURES
48-2.01D(2) Welding and Nondestructive Testing
Except for previously welded splices, welding must comply with AWS D1 .1. Welding of bar reinforcement must comply with AWS D1.4. Perform NDT on welded splices using UT or RT. Each weld and any repair made to a previously welded splice must be tested. You must select locations for testing. The length of a splice weld where N DT is to be performed must be a cumulative weld length equal to 25 percent of the original splice weld length. The cover pass must be ground smooth at test locations. Acceptance criteria must comply with the specifications for cyclically loaded nontubular connections subject to tensile stress in clause 8 of AWS D1.1. If repairs are required in a portion of the weld, perform additional NDT on the repaired sections. The NDT method chosen must be used for an entire splice evaluation, including any repairs. For previously welded splices, perform and document all necessary testing and inspection required to certify the ability of the falsework members to sustain the design stresses.
48-2.01D(3) Falsework Lighting
After the installation of falsework lighting, mea sure the illumination levels in the presence of the Engineer , during the hours of darkness . For pavement and pedestrian walkway lighting, the measurements must be taken at g round level with the meter sensor pointing upward. For portal lighting , measurement s must be taken at the face of the surface areas specified with the meter sensor perpendicular to the surface areas. Falsework lighting must comply wit h the illumination levels shown in the following table: Illumination Levels Illumination Area Average Illuminance (fc) (E avg) Uniformity (E avg/Emin) Pavement 0.6 4.0 Portal 1.0 4.0 Pedestrian Walkway 2.0 4.0
48-2.02 Materials
48-2.02A General
Wood must comply with the N DS. Timber used for falsework construction must be seasoned with moisture content not to exceed 19 percent .
48-2.02B Design Criteria
48-2.02B(1) General
Design falsework to resist the sum of the dead and live vertical loads and an assumed horizontal load. Anticipated falsework settlement must not exceed 1 inch. Design footings to carry the imposed loads without exceeding estimated soil bearing values or anticipated settlements. Falsework spans for T -beam girders must not exceed 14 feet plus 8.5 times the T -beam girder depth. Design falsework supporting deck slabs and overhangs on girder bridges such that there is no differential settlement between the girders and the deck forms during deck concrete placement. For individual steel towers with maximum leg loads exceeding 30 kips, design foundations to provide unifor m settlement under all legs of each tower. Design support systems for form panels supporting concrete deck slabs and overhangs on girder bridges as falsework. Temporary bracing must be designed to withstand all imposed loads during erection, construction, and removal of any falsework. Wind loads must be included in the design of the bracing. Falsework removal systems employing methods of holding falsework from above, and members of the independent support system, must support the sum of the actual vertical and horizontal loads due to falsework materials, equipment, construction sequence or other causes, and wind loading. Identifiable mechanical devices used in the falsework removal plan must comply with applicable industry standards SECTION 48 TEMPORARY STRUCTURES and manufacturer instruct ions for safe load carrying capacity. Unidentifiable winches must be capable of carrying twice the design load. The load used for the analysis of overturning moment and sliding of the winch system must be 150 percent of the design load. Where falsework for multiple level bridges is supported on the deck of a structure:
1.Falsework must bear directly on either: 1.1. Girder stems, bent caps, or end diaphragms of the supporting structure 1.2. Falsework sills that transmit the load to the girder stems, bent ca ps, or end diaphragms without applying any stress to the deck slab
2.Additional falsework must be in place beneath the supporting structure when construction loads are imposed on the supporting structure. Design and construct additional falsework to suppo rt all construction loads imposed on the supporting structure from the upper structure. Design the falsework lighting, for pavement, portals, and pedestrian walkways at or under falsework openings, to i lluminate:
1.Falsework portals during the hours of d arkness
2.Pavement, with portals less than 150 feet apart, during the hours of darkness
3.Pavement, with portals 150 feet or more apart, 24 hours a day
4.Pedestrian walkways 24 hours a day Lighting branch circuits must not exceed 20 A.
48-2.02B(2) Loads
The design load for falsework must consist of dead and live vertical loads, and an assumed horizontal load. The minimum total design load for any falsework for combined live and dead load is 100 psf, including members that support walkwa ys. Dead loads must include the weight of concrete, reinforcing steel, forms, and falsework. Loads due to concrete, reinforcing steel, and forms must be assumed to be at least:
1.160 pcf for normal concrete
2.130 pcf for lightweight concrete Live loads must include:
1.Actual weight of any equipment to be supported by the falsework applied as concentrated loads at the points of contact
2.Uniform load of at least 20 psf applied over the area supported by the falsework
3.Load of 75 lb/ft applied at the o utside edge of deck overhangs The assumed horizontal load the falsework bracing system must resist must be the sum of the actual horizontal loads due to equipment, construction sequence or other causes, and a wind loading. The assumed horizontal load in a ny direction must be at least 2 percent of the total dead load. If the concrete is to be prestressed, design the falsework to support any increased or readjusted loads caused by the prestressing forces. Design the falsework with sufficient rigidity to resi st the assumed horizontal load without considering the concrete load. For heavy -duty steel shoring or steel pipe column falsework with a vertical load capacity greater than 30 kips per leg or column, the minimum horizontal wind loading must be the sum of t he products of the wind impact area, shape factor, and wind pressure value for each height zone. The wind impact area is the total projected area of all elements in the tower face or falsework bent normal to the direction of the applied wind. Use a shape f actor of 2.2 for heavy -duty steel shoring and 1.0 for pipe column falsework. Use the wind pressure values shown in the following table: SECTION 48 TEMPORARY STRUCTURES Height zone , H (feet Wind pressure value above ground) Shores or columns adjacent to traffic (psf) At other locations (psf) H ≤ 30 20 15 30 < H ≤ 50 25 20 50 < H ≤ 100 30 25 H > 100 35 30 For all other falsework, the minimum horizontal wind loading must be the sum of the products of the wind impact area and the wind pressure value for each height zone. The wind impact area is the gross projected area of the falsework and any unrestrained portion of the permanent structure except for the areas between falsework bents or towers where diagonal bracing is not used. Use the wind pressure values shown in the following table: Height zone , H (feet above ground) Wind pressure value For members over and bents adjacent to traffic opening (psf) At other locations (psf) H ≤ 30 2.0 Q 1.5 Q 30 < H ≤ 50 2.5 Q 2.0 Q 50 < H ≤ 100 3.0 Q 2.5 Q H > 100 3.5 Q 3.0 Q NOTE: Q = 1 + 0.2 W, but not more than 10 where: W = width of the falsework system in feet, measured in the direction of the wind force Design falsework to support placement of the entire superstructure cross -section, except railing, at one time. You may consider girder stems and connected bottom slabs self -supporting between falsework posts if:
1.Girder stems and connected bottom slabs are placed more than 5 days before the top slab
2.Distance between falsework posts is at most 4 times the depth of the portion of the girder stem placed in the 1st pour Falsework for box girder structures with internal falsework bracing systems that use flexible members capable of withstanding only tensile forces must be designed to include (1) the vertical effects caused by elongation of the flexible member and (2) the design horizontal load combined with the dead and live loads imposed by concrete placement for girder stems and connected bottom slabs. This requirement does not apply to falsework composed of individual steel towers that use flexible members capable of withstanding only tensile forces to resist overturning.
48-2.02B(3) Stresses, Loadings, and Deflections
48-2.02B(3)(a) General
Maximum allowable stresses and loadings specified in section 48 -2.02B(3) are based on the use of undamaged high -quality materials. Reduce stresses and loadings for materials of lesser quality. Deflection due to reinforced concrete loading only must not exceed 1/240 of the span length.
48-2.02B(3)(b) Timber
Design stres ses for timber and timber connections must not exceed stresses specified in the current NDS. Adjustment factors used to determine allowable stresses for timber members and connections must comply with NDS for the appropriate condition of use and species. Pile design load for timber piles must not exceed 45 tons. SECTION 48 TEMPORARY STRUCTURES
48-2.02B(3)(c) Steel
Except for flexural compressive stresses, the design load for identified grades of steel must not exceed the allowable strength specified in the AISC Steel Construction Manual . Except for flexural compressive stresses, the design load for unidentified steel must not exceed the allowable strength specified for steel complying with ASTM A36/A36M in the AISC Steel Construction Manual or as shown in the following table: Quality characteristic Requirement Tension, axial and flexural (psi) 22,000 Compression, axial (psi) 16,000 -0.38( L/r)2 a Shear on gross section of web of rolled shapes (psi) 14,500 Web yielding for rolled shapes (psi) 27,000 Modulus of elasticity (E) (psi) 30 x 106 NOTES: L = unsupported length, inches r = radius of gyration of the member, inches aL/r must not exceed 120 . Design stresses and deflections for all grades of steel must not exceed the requirements shown in the following table: Quality characteristic Requirement Compression, flexural (psi) 12,000,000 /[(L x d)/(b x t)]a Modulus of elasticity (E) (psi) 30 x 106 NOTES: L = unsupported length, inches d = least dimension of rectangular columns or the width of a square of equivalent cross -sectional area for round columns, or the depth of beams, inches b = width of the compression flange, inches t = thickness of the compression flange, inches Fy = specifie d minimum yield stress in psi aNot to exceed (1) 22,000 psi for unidentified steel, (2) 22,000 psi for steel complying with ASTM A36/A36M, or (3) 0.6 Fy for other identified steel .
48-2.02B(3)(d) Manufactured Assemblies
Do not exceed the manufacturer's instructions for loadings and deflections on jacks, brackets, columns, joists, and other manufactured devices except the dead load deflection of joists at locations other than under deck slabs between girders must not exceed 1/240 of their s pans.
48-2.02B(4) Special Locations
Design and construct falsework over or adjacent to roadways or railroads that are open to traffic such that the falsework is stable if subjected to impact by vehicles. Falsework posts at the following locations are cons idered adjacent to roadways or railroads:
1.Posts supporting members that cross over a roadway or railroad
2.Posts located in the row of falsework posts nearest to the roadway or railroad and where the horizontal distance from the traffic side of the fal sework to the edge of pavement or to a point 10 feet from the centerline of track is less than the total height of the falsework and forms The falsework design at the above locations must comply with section 48 -2.02B and the following requirements:
1.The vertical load used for the design of falsework posts and towers that support the portion of the falsework over openings must be the greater of: 1.1. 150 percent of the design load calculated under section 48 -2.02B(2), not including any increased or readju sted loads caused by prestressing forces SECTION 48 TEMPORARY STRUCTURES 1.2. Increased or readjusted loads caused by prestressing forces
2.Falsework posts must be steel with a minimum section modulus about each axis of 9.5 cubic inches or sound timbers with a minimum section modulus ab out each axis of 250 cubic inches.
3.Each falsework post must be mechanically connected to the support footing at its base or laterally restrained to withstand a force of at least 2,000 lb applied at the base of the post in any direction except toward the roadway or railroad track. Posts must be mechanically connected to the falsework cap or stringer. The mechanical connection must resist a load in any horizontal direction of at least 1,000 lb.
4.Mechanically connect (1) exterior falsework stringers, (2) stringers adjacent to the ends of discontinuous caps, (3) stringers over points of minimum vertical clearance, and (4) every 5th remaining stringer to the falsework cap or framing. For falsework over railroads, mechanically connect all stringers to caps. M echanical connections must resist at least a 500 lb load in any direction, including uplift on the stringer. Install connections before traffic passes under the span.
5.Connect timber bracing to falsework using at least 5/8 -inch-diameter bolts or coil rod with a root diameter equal to that of the shank of a 5/8 -inch-diameter bolt.
6.Falsework member minimum clear area width must comply with section 12 -3.20C(1) and the requirements specified in the following table: Minimum Clear Area Width Falsework member To permanent railing members and barriers Footings 0'-3" Piles 2'-6" Other members 2'-6"
7.Falsework bents within 20 feet of the centerline of a railroad track must be sheathed solid from 3 to 17 feet above the track on the side facing the track. Sheathing must be plywood at least 5/8 inch thick or lumber at least 3/4 inch thick. Brace these bents to resist the required assumed horizontal load or 5,000 lb, whichever is larger.
8.Provide clear openings through falsework as describ ed.
48-2.02C Falsework Lighting
48-2.02C(1) General
A falsework luminaire must:
1.Be commercially available
2.Include brackets and locking screws
48-2.02C(2) Pavement Illumination
Reserved
48-2.02C(3) Portal Illumination
Portal illumination include s plywood clearance guides 4 feet wide by 8 feet high and luminaires.
48-2.02C(4) Pedestrian Walkway Illumination
Reserved
48-2.03 Construction
48-2.03A General
Install temporary bracing as necessary to withstand all imposed loads during erection, construction, and removal of any falsework. The materials used in the falsework construction must be of the quality necessary to sustain the stresses required by the falsework design. During concrete placement , if (1) events occur that the Engine er determines will result in a structure that does not comply with the structure as described or (2) settlement variance is greater than 3/8 -inch from the values shown on shop drawings, stop concrete placement and apply corrective measures. If the SECTION 48 TEMPORARY STRUCTURES measures are not provided before initial concrete set occurs, stop concrete placement at the location ordered. Detour traffic from the lanes over which falsework is being erected, released, adjusted, or removed.
48-2.03B Found ations
Construct falsework on solid footings capable of supporting falsework loads. Protect footings from softening and undermining. The Engineer determines if you must verify that the design soil bearing values do not exceed the soil capacity using load t esting. You may place falsework foundation pads and piles before shop drawings are authorized. Falsework piles must be driven and assessed under section 49. The actual nominal driving resistance must be at least twice the falsework pile design load. For pi le acceptance, the required number of hammer blows in the last foot of driving is determined using the formula in 49 -2.01A(4)(c).
48-2.03C Erection
Construct falsework to support the loads imposed without settlement or take -up beyond that shown on the falsework drawings. Install the final bracing system before placing falsework members above stringers. Falsework erection includes adjustments or removal of components that contribute to the horizontal stability of the falsework system. If falsework is over o r adjacent to roadways or railroads, all details of the falsework system that contribute to horizontal stability and resistance to impact, except for bolts in bracing, must (1) be installed when each element of the falsework is erected and (2) remain in pl ace until the falsework is removed. If ordered, use camber strips to compensate for falsework deflection, vertical alignment, and anticipated structure deflection. The Engineer furnishes the amount of camber to be used in constructing falsework. Install te ll-tales that (1) are attached to the soffit forms and (2) can be read from the ground. Provide sufficient tell -tales to allow the total settlement where concrete is being placed to be determined. Construct deck slab forms between girders with no allowance for settlement relative to the girders. Do not apply dead loads other than forms and reinforcing steel to falsework until authorized.
48-2.03D Removal
Release and r emove falsework such that portions of falsework to be removed remain stable. Falsework rel ease includes blowing sand from sand jacks, turning screws on screw jacks, and removing wedges. Except for concrete above the deck, do not release falsework supporting any span of a:
1.Simple span bridge before 10 days after the last concrete has been pla ced
2.Continuous or rigid frame bridge before 10 days after the last concrete has been placed: 2.1. In that span 2.2. In adjacent portions of each adjoining span for a length equal to one -half of the span where falsework is to be released
3.Simple span, continuous, or rigid frame bridge until the supported concrete has attained a compressive strength of 2,880 psi or 80 percent of the specified strength, whichever is greater Do not release falsework for prestressed portions of structures until prest ressing steel has been tensioned. Do not release falsework supporting any span of a continuous or rigid frame bridge until all required prestressing is complete (1) in that span and (2) in adjacent portions of each adjoining span for a length equal to at l east one half of the span where falsework is to be released. Release falsework supporting spans of CIP girders, slab bridges, or culverts before constructing or installing railings or barriers on the spans, unless authorized. SECTION 48 TEMPORARY STRUCTURES Release falsework for arch bri dges uniformly and gradually. Start at the crown and work toward the springing. Release falsework for adjacent arch spans concurrently. Do not release falsework that supports overhangs, deck slabs between girders, or girder stems that slope 45 degrees or m ore from vertical before 7 days after deck concrete has been placed. You may release falsework supporting the sides of girder stems that slope less than 45 degrees from vertical before placing deck concrete if you install lateral supports. Lateral supports must be:
1.Designed to resist rotational forces on the girder stem, including forces due to concrete deck placement
2.Installed immediately after each form panel is removed
3.Installed before releasing supports for the adjacent form panel Do not relea se falsework for bent caps supporting steel or PC concrete girders before 7 days after placing bent cap concrete. Release falsework for structural members subject to bending as specified for simple span bridges. Do not release falsework for box culverts an d other structures with decks lower than the roadway pavement and span lengths of 14 feet or less until the last placed concrete has attained a compressive strength of 1,600 psi. Curing of the concrete must not be interrupted. Falsework release for other b ox culverts must comply with the specifications for the release of bridge falsework. Do not release falsework for arch culverts sooner than 40 hours after concrete has been placed. Remove falsework piling to at least 2 feet below the original ground or str eambed. Remove falsework piling driven within ditch or channel excavation limits to at least 2 feet below the bottom and side slopes of the excavated areas. Falsework removal systems employing methods of holding falsework by winches, hydraulic jacks with prestressing steel, HS steel rods, or cranes must also be supported by an independent support system when the falsework is over vehicular, pedestrian, or railroad traffic openings open to traffic. Bridge deck and soffit openings used to facilitate falsework removal activities must:
1.Have a 6 -inch maximum diameter opening
2.Be located away from the wheel paths for deck openings
3.Be formed with corrugated HDPE pipe complying with section 20 -2.07B(3) Before filling the bridge deck and soffit openings with concrete:
1.Trim HDPE pipes 1 inch from the exposed surface of the top of deck, bottom overhang, and soffit.
2.Clean and roughen concrete surfaces of opening. Fill the opening with rapid setting concrete complying with section 60 -3.02B(2) or with a conc rete mix of equal or higher strength than the deck. Finish surface must comply with section 51 -1.03F(2). Falsework removal over roadways with a vertical traffic opening of less than 20 feet must start within 14 days after the falsework is eligible to be released and must be completed within 45 days after it is eligible to be released.
48-2.03E Falsework Lighting
48-2.03E(1) General
Notify the Engineer at least 5 business days before the installation of the falsework lighting . Fasten power cables to the supporting structure at a minimum 3 -foot intervals and within 12 inches from every box. Encase cables within 8 feet of the ground in a minimum 1/2-inch Type 1 conduit. Enclose splices in junction boxes. Provide power for the falsework lighting under section 87 -20. Energize lighting circuits immediately after supporting structure s have been erected . SECTION 48 TEMPORARY STRUCTURES
48-2.03E(2) Pavement Illumination
Provide pavement illumination on roadways beneath falsework structure s. Install luminaires:
1.Along the sides of the openi ng not more than 4 feet behind or 2 feet in front of the roadway face of the temporary barrier system
2.12 to 16 feet above the roadway surface without obstructing the light pattern on the pavement
3.Aimed to avoid glare to motorists
4.Spaced to comply with the illumination levels table
5.At the ends no more than 10 feet inside portal faces Measure the illumination levels at a minimum two points per lane, one on each side within one-quarter of the lane width from the lane stripe. Use this pattern to st art the measurements at both ends of the falsework and then at 15 -foot intervals through the length of the pavement under the falsework.
48-2.03E(3) Portal Illumination
Provide portal illumination on the side s facing traffic. Install luminaires and clearance guides immediately after falsework vertical members are erected. Fasten clearance guides:
1.To the vertical support adjacent to the traveled way, facing traffic
2.Vertically with the bottom of the clearance guide from 3 to 4 feet above the roadway
3.With the center located approximately 3 feet horizontally behind the face of the temporary barrier system on the roadway side Paint clearance guides before each installation with not less than 2 applications of flat white paint. If ordered, repaint ing is change order work. Install luminaires on the structure directly over the vertical support , approximately 16 feet above the pavement and 6 feet in front of the guides. Aim the luminaires to illuminate the exterior falsework beam, the clearance guides, and the overhead clearance sign and comply with the illumination levels table . Measure the illu mination levels at the center and four corners of the clearance guides, at the exterior falsework beam, and at the overhead clearance sign .
48-2.03E(4) Pedestrian Walkway Illumination
Provide pedestrian walkway illumination immediately after the protective overhead covering is erected. Install the luminaires a minimum 8 feet clea rance in the protective overhead covering and center them over the pedestrian walk way. Space the luminaires through the pedestrian walkway as needed to comply with the illumination levels table. Install luminaires at the ends no more than 7 feet inside the pedestrian walkway openings. Measure the illumination levels at a minimum two points, one on each side within one-quarter of the walkway width from the edge. Use this pattern to start the measurements at both ends of the falsework and then at 10-foot intervals through the length of the pedestrian walkway.
48-2.04 Payment
Not Used
48-3 Temporary Supports
48-3.01 General
48-3.01A Summary
Section 48 -3 includes specifications for providing temporary supports for structures during retrofit, reconstruction, erection, and removal activities. Jacking assemblies, accessories, and activities required to jack and support structures must comply with section 48 -5. SECTION 48 TEMPORARY STRUCTURES Falsework must comply with section 48 -2.
48-3.01B Definitions
Reserved
48-3.01C Submittal s
48-3.01C(1) General
Submit 2 copies of the initial location survey of the existing structure sealed and signed by an engineer who is registered as a civil engineer in the State. Submit a copy of the displacement monitoring record after completing the work.
48-3.01C(2) Shop Drawings
Submit the following:
1.Descriptions and values of all loads, including construction equipment loads.
2.Descriptions of equipment to be used.
3.Details and calculations for jacking and supporting the structure.
4.Stress sheets, anchor bolt layouts, shop details, erection plans, and removal plans for the temporary supports.
5.Assumed soil bearing values and design stresses for temporary support footings, including anticipated foundation settlement.
6.Maximum dista nce temporary -support piles may be pulled for placement under footing caps.
7.Maximum deviation of temporary -support piles from a vertical line through the point of fixity.
8.Details for use of permanent piles. Include any additional loads imposed on the piles.
9.Details for additional bracing required during erection and removal of temporary supports.
10.Details of the displacement monitoring system, including equipment, location of control points, and methods and schedule for taking measurements.
11.Mitigation plan for jacking the structure if settlement occurs in the temporary supports. Calculations must show a summary of computed stresses in (1) temporary supports, (2) connections between temporary supports and the structure, and (3) load -supportin g members. The computed stresses must include the effect of the jacking sequence. Calculations must include a lateral stiffness assessment of the temporary support system. Shop drawings and calculations must be seal and signed by an engineer who is registe red as a civil engineer in the State.
48-3.01D Quality Assurance
48-3.01D(1) General
Welding, welder qualification, and welding inspection for temporary supports must comply with AWS D1.1.
48-3.01D(2) Quality Control
Reserved
48-3.02 Materials
48-3.02A General
Manufactured assemblies must comply with section 48 -2.02B(3)(d).
48-3.02B Design Criteria
The Engineer does not authorize temporary support designs based on allowable stresses or design load greater than those specified in section 48 -2.02B(3). If falsework loads are imposed on temporary supports, the temporary supports must also satisfy the deflection criteria in section 48 -2.02B(3). The temporary support system must support the initial jacking loads and the minimum temporary support design loads and forces shown. As a minimum, the horizontal load to be resisted in any direction by the temporary support system must be (1) the sum of actual horizontal loads due to equipment, construction SECTION 48 TEMPORARY STRUCTURES sequence, or other causes plus an allowance for wind and (2) not less than 10 percent of the total supported dead load at the location being considered. Adjust vertical design loads for the weight of the temporary supports and jacking system, construction equipment loads, and additional loads imposed by jacking acti vities. Construction equipment loads must be at least 20 psf of deck surface area of the frame involved. For column repair or removal, the temporary supports must resist the described lateral design forces applied at the point where the column to be remove d meets the superstructure. Stiffness of temporary supports must match the described minimum stiffness. If the temporary support stiffness exceeds the described minimum stiffness, increase the lateral design forces to be compatible with the temporary suppo rt lateral stiffness. Place temporary supports , that are resisting transverse lateral loads , within 1/2 of the span length from the existing bent. Place temporary supports , that are resisting longitudinal lateral loads , within the frame where columns are t o be removed. You may use the permanent piles as part of the temporary support foundation. Do not move or adjust permanent piles from the locations shown. If you install permanent piles longer than described to support the temporary supports above the top of the footing and later cut off the piles at their final elevation, you must use shear devices adequate to transfer all pile reactions into the footing. Design temporary support footings to carry the loads imposed without exceeding the estimated soil bearing values or anticipated settlements. You must determine soil bearing values. Where temporary supports are placed on the deck of an existing structure:
1.Temporary supports must bear either: 1.1. Directly on girder stems, bent caps , or end diaphragms of the supporting structure 1.2. On falsework sills that transmit the load to the stems, bent cap , or end diaphragms without overstressing any member of the new or existing structure
2.Temporary supports must not induce permanent forces into the complete d structure or produce cracking.
3.Place additional temporary supports beneath the existing structure where temporary support loads are imposed on the existing structure. Design and construct the additional temporary supports to support all loads from the upper structure and construction activities. Provide additional bracing as required to withstand all imposed loads during each phase of temporary support erection and removal. Include wind loads complying with section 48 -2.02B(2) in the design of additio nal bracing. For bridge removal, the temporary support system must resist the design loads and forces shown. As a minimum, the horizontal load to be resisted in any direction for temporary support shoring and temporary bracing must be (1) the sum of actual horizontal loads due to equipment, construction sequence, or other causes plus an allowance for wind and (2) not less than 10 percent of the total dead load of the structure being removed. Mechanically connect (1) the structure to the temporary supports a nd (2) the temporary supports to their foundations. Mechanical connections must be capable of resisting the lateral design forces. Friction forces developed between the structure and temporary supports (1) are not considered an effective mechanical connect ion and (2) must not be used to reduce lateral forces. Design mechanical connections to accommodate movement resulting from adjustments made to the temporary support s. If the concrete is to be prestressed, design temporary supports to support changes to the loads caused by prestressing forces. Temporary supports must comply with the specifications for falsework in section 48 -2.02B(4).
48-3.03 Construction
Where described, install temporary crash cushion modules under section 12 -3.22 before sta rting temporary support activities. Remove crash cushion modules when authorized. SECTION 48 TEMPORARY STRUCTURES Construct and remove temporary supports under the specifications for falsework in section 48 -2.03. If traffic is carried on the structure on temporary supports, do not releas e temporary supports until the supported concrete has attained 100 percent of the described strength. Remove attachments from the existing structure. Restore concrete surfaces to original conditions except where permanent alterations are shown.
48-3.04 Pa Yment
Payment for crash cushion modules is not included in the payment for temporary support.
48-4 Temporary Decking
48-4.01 General
48-4.01A Summary
Section 48 -4 includes specifications for temporary decking for joint or deck reconstruction. Temporary decking must consist of a steel plate system that spans the incomplete work. Concrete anchorage devices and nonskid surface must comply with section 75 -3.
48-4.01B Definitions
Reserved
48-4.01C Submittals
Submit shop drawings and calculations for temporary decking. Shop drawings and calculations for temporary decking must be sealed and signed by an engineer who is registered as a civil engineer in the State. Temporary decking shop drawings and calculations must include:
1.Storage location of equip ment and materials that allows for 1 shift of work and placement of temporary decking within the time allowed
2.Construction sequence and schedule details
3.Cure time for concrete to be placed under temporary decking
4.Details for removing temporary dec king and restoring the existing structure If temporary decking is not shown, shop drawings and calculations must also include:
1.Design calculations, including the d escription, location, and value , of all loa ds
2.Details of the connection between the te mporary decking and the existing or new structure Submit a certificate of compliance for temporary decking materials. Sections 48 -1.01C(2), 48 -1.01C(3), and 48 -1.01D(2) do not apply for temporary decking.
48-4.01D Quality Assurance
Reserved
48-4.02 Mate Rials
48-4.02A General
Yield strength of s teel plate must be greater than or equal to 36 ksi . Bolts must comply with ASTM F3125, Grade A325. Nuts must comply with ASTM A563/563M. Material for temporary tapers must be rapid setting concrete or polyester co ncrete comply ing with section
60-3.02B(2) or 60 -3.04B(2).
48-4.02B Design Criteria
If temporary decking is not shown, the temporary decking design must : SECTION 48 TEMPORARY STRUCTURES
1.Comply with the unfactored permit loads, braking force, and HL93 loads except lane load from the current AASHTO LRFD Bridge Design Specifications with California Amendments .
2.Not exceed the allowable stresses or design load s specified in section 48 -2.02B(3) .
3.Have live load deflection not exceeding 1/300 of the temporary decking span for the desig n load.
4.Provide for temporary decking with a uniform surface with a coefficient of friction of at least 0.35 when measured under California Test 342.
5.Provide for temporary decking that is mechanically connected to the existing structure and adjacent approaches. If a steel plate spans a joint, the mechanical connection must accommodate at least 50 percent of the movement range shown for that joint.
6.Not overstress, induce permanent forces into, or produce cracking in the existing structure.
48-4.03 Construction
For bolted connections, drill the holes without damaging the adjacent concrete. Do not damage existing reinforcement. If the temporary decking does not extend the entire width of the roadway, taper the sides of the temporary decking at a 12:1 (horizontal: vertical) ratio. Cure temporary tapers at least 3 hours before allowing traffic on the temporary decking. If unanticipated displacements, cracking, or other damage occurs to the e xisting structure or to any new components installed in or adjacent to the deck, stop work on the deck and perform corrective measures. Edges of steel plate systems must be in full contact with the existing deck and the adjacent approach slab. If used, shi ms must be securely attached to the plate. Do not allow traffic on deck concrete until it has attained the compressive strength shown. When temporary decking is no longer needed, immediately remove temporary decking materials and connections from the exist ing structure. Patch holes with rapid setting concrete complying with section
60-3.02 Remove modifications to the existing structure except where permanent alterations are shown.
48-4.04 Payment
Not Used
48-5 Jacking
48-5.01 General
48-5.01A Summary
Section 48 -5 includes specifications for jacking the bridge superstructure using a jacking support system.
48-5.01B Definitions
Reserved
48-5.01C Submittals
The submittal for shop drawings and calculations must include :
1.Descriptions, locations, and values of all loads, including construction equipment loads
2.Jacking construction sequence including staging areas for equipment and materials for jacking support systems
3.Type, model number, and weight of equipment to be used including: 3.1. Jack capacity 3.2. Certified calibration chart for each jack 3.3. Certified indicator to determine jacking force
4.Details and calculations with the load paths for jacking and supporting the structure including a redundant system of supports to ensu re stability of the jacking system during jacking activities
5.Stress sheets, anchor bolt layouts, shop drawing details, and erection and removal plans for the jacking support system
6.Assumed soil bearing values and design stresses for support footings, including anticipated foundation settlement
7.Details for bracing required during erection and removal SECTION 48 TEMPORARY STRUCTURES
8.Details of the displacement monitoring system, including equipment, location of control points, and methods and schedule of taking measurements
9.Any additions or modifications to the structure in connection with the jacking support systems including: 9.1. Temporary strengthening and stiffening members 9.2. Permanent stiffening members
10.Mitigation plan for jacking the structure if settlement occur s Calculations must show a summary of computed stresses in the jacking support system and the connections between the jacking support system and the bridge superstructure. The computed stresses must include the effect of the jacking sequence. Shop drawing s and calculations must be sealed and signed by an engineer who is registered as a civil engineer in the State. Submit the displacement monitoring records.
48-5.01D Quality Assurance
48-5.01D(1) General
Calibrate each jack within 6 months of use and afte r each repair. Each jack and its gauge must (1) be calibrated as a unit with the cylinder extension in the approximate position that it will be at the final jacking force and (2) accompanied by a certified calibration chart. Each load cell must be calibrat ed. Calibration must be performed by an authorized laboratory.
48-5.01D(2) Displacement Monitoring
Perform an initial survey to record the location of the structure before starting work. Monitor and record vertical and horizontal displacements of the jack ing support system and the structure. Use vandal - resistant displacement monitoring equipment. Perform monitoring continuously during jacking activities. Make monitoring records available at the job site during normal work hours. Monitoring records must be sealed and signed by an engineer who is registered as a civil engineer in the State. As a minimum, monitor the structure at the supported or jacking locations and at the midspan of both adjoining spans. Locate control points at each location near the cente r and at both edges of the superstructure. As a minimum, record elevations at the following times:
1.Before starting jacking activities
2.Immediately after completing jacking
3.After completing bridge removal
4.Before connecting the superstructure to the substructure
5.After removing the jacking support system
48-5.02 Materials
48-5.02A General
Reserved
48-5.02B Design Criteria
The jacking support system must resist the structure dead load and lateral design forces shown, plus an y additional loads from jacking equipment and activities. As a minimum, the horizontal load to be resisted in any direction for the jacking support system and temporary bracing must be (1) the sum of actual horizontal loads due to equipment, construction s equence, or other causes plus an allowance for wind as specified in section 48 -2.02B(2) and (2) not less than 10 percent of the total dead load of the structure being jacked. If the jacking support system lateral stiffness exceeds the described minimum sti ffness, increase the lateral design forces to be compatible with the jacking support system lateral stiffness. Systems involving modifications to the bridge that impair the structural integrity, intended serviceability, or design capacity of the bridge are not allowed. SECTION 48 TEMPORARY STRUCTURES
48-5.03 Construction
Equip each jack with a pressure gauge or load cell for determining the jacking force. Each pressure gauge must have an accurately reading dial at least 6 inches in diameter. Each load cell must be provided with an indica tor to determine the jacking force. Provide a redundant system of supports to ensure stability of the jacking system during jacking activities. Stop jacking activities if unanticipated displacements, cracking, or other damage occurs. Corrective measures mu st be authorized and implemented before resuming jacking activities. Before starting jacking activities at a location being supported, the jacking support system must (1) apply a force to the structure that is equal to the initial jacking load or the dead load shown and (2) hold that load until all initial compression and settlement of the system is completed. During jacking activities, apply loads simultaneously. Control and monitor jacking operations to prevent distortion and stresses that would damage th e structure. Maintain total vertical displacements at control points to less than 1/4 inch from elevations recorded before jacking or as authorized. Jack the superstructure uniformly to the position described. Distribute the load uniformly across each hinge, abutment, bent , or span . If authorized, place galvanized shims as necessary to provide uniform loading at bearing pads. After reconstruction activities, the monitored control points must not deviate by more than 1/4 inch from the initial vertical survey elevations or other authorized elevations. Remove attachments required for jacking from the superstructure and apply the described finish to concrete surfaces .
48-5.04 Payment
Not Used
48-6 Temporary Wood Poles
48-6.01 General
48-6.01A Summary
Section 48-6 includes specifications for constructing, maintaining, and removing temporary wood poles for the support of electrical systems. Temporary wood poles include attached wire components.
48-6.01B Definitions
Reserved
48-6.01C Submittals
48-6.01C(1) General
Submit a letter of certification that certifies all components of the manufactured assemblies are used in compliance with the manufacturer's recommendations. If requested, (1) submit manufacturer's data for manufactured assemblies to v erify manufacturer's recommendations or (2) perform tests demonstrating adequacy of the proposed assemblies and submit the test results. Submit the letter before installing messenger wires, tether wires, or self -supporting conductors or cables. You may sub mit a request to use alternative mounting brackets or wire termination hardware. Your request must include:
1.Structural design calculations and testing data sealed and signed by an engineer who is registered as a civil engineer in the State
2.Manufactur er's instructions Sections 48 -1.01C(2), 48 -1.01C(3), and 48 -1.01D(2) do not apply for temporary wood poles. SECTION 48 TEMPORARY STRUCTURES
48-6.01C(2) Guy Wire Anchors
Submit the guy wire anchor manufacturer's product information and installation instructions. Do not install anchors u nless authorized.
48-6.01D Quality Assurance
48-6.01D(1) General
A temporary -structure engineer is not required.
48-6.01D(2) Welding
Welding must comply with AWS D1.1.
48-6.02 Materials
48-6.02A General
Wire used for messenger wires, tether wires, or guy wires must be 7 -wire strand complying with ASTM A475, Utilities Grade. Connection hardware for wires must provide a termination efficiency factor of not less than 0.80. Wood poles, push braces, and stubs must comply with ANSI O5.1. Treat wood under AWP A U1, Use Category UC4B, Commodity Specification D. Except for wire, helical anchors, expanded steel plate anchors, cross plate anchors, and expanding rock anchors, steel components must comply with section 56 -3.
48-6.02B Helical Anchors, Expanded Steel Plate Anchors, Cross Plate Anchors, and Expanding
Rock Anchors Fabricate helical anchors, expanded steel plate anchors, and cross plate anchors under section 75. Fabricate attachable thimble eyes and expanding rock anchors from suitable ferrous mater ial. Fabricate as a continuous piece or as separate segments with mechanical connections between segments. Include integral thimble eye or include attachable thimble eye. Galvanize all helical anchor parts under section 75. Paint expanded steel plate ancho rs, cross plate anchors, and expanding rock anchors as specified for repairing damaged galvanized surfaces in section 75 -1.02B. The final assembly must have (1) a minimum ultimate tensile strength greater than the minimum required breaking strength of the guy wire and (2) a minimum ultimate torsional strength greater than twice the minimum installation torque.
48-6.02C Reuse of Materials and Relocation of Temporary Supports
You may reuse structural components and relocate temporary supports provided that t he materials remain in acceptable condition for reuse, except do not reuse:
1.Components of high -strength bolt assemblies that have been or are required to be tensioned past snug tight
2.High-strength cap screws that have been or are required to be tensi oned past snug tight
3.Tension control bolts
48-6.03 Construction
48-6.03A General
Install construction bracing as necessary to withstand all imposed loads during erection, construction, and removal of any temporary wood poles. Install a temporary barr ier system at temporary wood pole locations that are less than 15 feet from the edge of a traffic lane. Install temporary barrier system before erecting temporary wood poles. Do not remove temporary barrier system until authorized. SECTION 48 TEMPORARY STRUCTURES For overhead line constr uction not specifically covered in the contract documents, comply with Public Utility Commission General Order 95.
48-6.03B Foundations
Verify the design soil parameters before starting construction of temporary wood poles. Remove any accumulated water fr om the pole excavation prior to placing granular backfill at the bottom of the pole excavation. Thoroughly compact and level the granular backfill at the bottom of the pole excavation prior to setting the pole. Backfill around poles with manufactured sand that is free of rocks or other deleterious material. Place the backfill material in 4 -inch-thick layers. Moisten and thoroughly compact each layer. Remove accumulated water from the anchor excavation prior to placing an expanded steel anchor. Expand the ba se of the expanded steel anchor prior to placing backfill. Place backfill around the expanded steel anchor in 4 -inch thick layers. Thoroughly compact each layer. Protect foundations from softening and undermining.
48-6.03C Erection
If temporary wood poles are over or adjacent to roadways or railroads, all construction bracing must (1) be installed at the time each element of the temporary wood pole is erected and (2) remain in place until the temporary wood pole is removed. Suspend conductors from messenger wire by continuous lashing wire. No spare wire conductors or cables are allowed unless described. Sag overhead bundles to maintain required clearances over the ambient temperature range from -30 to 120 degrees F. The sag must be between 4.6 and 5 .4 percent of horizontal span unless otherwise shown. Minimum vertical clearance over grade is 25 feet unless otherwise shown.
48-6.03D Attachments
If specific connection details are not shown, mount attachments under the manufacturer's written instructio ns and such that there is no loss of cross section.
48-6.03E Damping
If at any time during service the temporary structural support exhibits excessive vibration, immediately install dampers. Dampers must be effective in mitigating the vibration and must n ot compromise the structural supports or the supported hardware.
48-6.03F Removal
Remove temporary structural supports such that portions not yet removed remain stable at all times. Remove temporary wood poles and helical anchors. Fill the void with excav ated material or sand that is free of deleterious material. Place the backfill material in 4 -inch-thick layers. Moisten and thoroughly compact each layer. Dispose of surplus excavated material uniformly along the adjacent roadway. Dispose of temporary stru ctural support materials and work debris.
48-6.03G Guy Wire Helical Anchors
48-6.03G(1) General
Reserved
48-6.03G(2) Installation Parameters
Use the minimum installation torque shown. You may request an alternative minimum installation torque based on a revised value for empirical torque factor. For alternative minimum installation torque, use the following equation to calculate the installation torque: T = Qa(FS/Kt) SECTION 48 TEMPORARY STRUCTURES where: T = Minimum installation torque, ft -lb FS = Factor of safety of 2.0 Qa = Minimum allowable tensile capacity shown, lb Kt = Empirical torque factor, 1/ft (inverse foot) Include a geotechnical report sealed and signed by a licensed geotechnical engineer with recommended values for empirical torque factor and alternative minimum install ation torque with your request. Do not start installation unless your alternative installation parameters are authorized. Verify the installation parameters before the start of anchor installation.
48-6.03G(3) Installation
Install anchors under the manufacturer's written instructions and the following:
1.Do not install anchors underneath utilities or subsurface structures.
2.Maintain horizontal clearances as required by the Engineer.
3.Install to the minimum embedment length.
4.Continuously monit or and record torque during installation. If torque at the minimum embedment length is not equal to or greater than the minimum required, continue installation to greater embedment until the minimum installation torque is achieved for 2 continuous feet.
48-6.03G(4) Removal
After service is complete, remove anchors using reverse torque. Fill the void with excavated material or sand free of deleterious materials. Place the backfill material in 4 -inch-thick layers. Moisten and thoroughly compact each layer.
48-6.03H Expanded Steel Plate Anchors, Cross Plate Anchors, and Expanding Rock Anchors
48-6.03H(1) General
Reserved
48-6.03H(2) Installation
Install anchors under the manufacturer's written instructions. Locate and mark all substructures and utilities. Do not install anchors underneath subsurface utilities or structures.
48-6.03H(3) Removal
After service is complete, remove anchors to a depth of at least 3 feet below finished grade. Fill the void with sand free of deleterious materials. Place the backfi ll material in 4 -inch-thick layers. Moisten and thoroughly compact each layer.
48-6.04 Payment
Not Used
48-7 48-10 Reserved
Source: California Standard Specifications, 2024 Edition. Pages 695–716 of 1,372.